One in three patients high blood pressure are failing to take medication as prescribed by their healthcare professionals, according to a new study by UK researchers who used an innovative new test.
The study used a novel urine test, which was designed by University Hospitals of Leicester NHS Trust and Leicester University, to help to diagnose adherence to blood pressure medications.
“This is a simple, relatively inexpensive and a robust test”
The study, involving 1,400 hypertensive patients, saw the test used to find that non-adherence to prescribed medications was around 30-40%.
Non-adherence to medications has previously been found to be one of the important reasons for the lack of blood pressure control in at least 50% of the patients in the study.
A crucial reason for the lack of progress in improving adherence has been the previous lack of a clinically useful objective measure to show when people are not taking their prescribed medicine.
The researchers said they had worked to develop a robust and reliable biochemical screening method to assess for non-adherence to antihypertensive medications in urine or blood.
The test uses a technique called liquid chromatography-tandem mass spectrometry.
The team set up a National Centre for Adherence Testing at Leicester’s Hospitals and received samples from around 25 hypertension clinics across UK.
The Leicester researchers also collaborated with colleagues in Manchester and the Czech Republic.
The study showed that more than 41.6% of the UK cohort and 31.5% of the Czech cohort were non-adherent to their anti-hypertensive medications.
In addition, 14.5% of the UK and 12% of the Czech cohort were not taking any medications, found the study published in the journal Hypertension.
Crucially, non-adherence was related to the number of prescribed medications with the risk increasing by more than 75% with each increase in medication and it was highest with diuretics.
Younger patients and females were also found to have an increased risk of non-adherence to prescribed medications.
Lead study author Dr Pankaj Gupta said: “Given the high prevalence of non-adherence, we should assess patients, particularly those on multiple antihypertensive medications or those who do not have an expected response to treatment”
Dr Prashanth Patel, also a study lead co-author, added: “This is a simple, relatively inexpensive and a robust test. It and has anecdotally changed the management of hypertension in many centres who use the test.”
The researchers said they hoped to ascertain whether non-adherent patients, on follow up, improved their behaviour and if adherence testing led to an improvement in blood pressure.